I ran into this very problem when I worked on my books. Since everyone seems to have their own ideas, I figured I couldn't make everyone happy, so I came up with a very complex system that would count as much as possible and work for all the many series of TF's. (including Japanese series) I counted all named characters unless they were sold as an accessory to a figure. All Nebulans we're counted as part of the toy along with guys like Roller and Sixgun. Micromasters were counted as individual characters as would have Mini-cons had I got to those books. I counted Combiners as a character as well as their separate parts. I did this cause every media format seemed to go that way with them. As I did with my Index, I counted all same-named characters as seperate characters since they could only exist at different times. For example, G1 Optimus was numbered 01 since he was the first while the Powermaster version was 02 despite them being the same bot cause he was no longer in his original body. I counted Armada's Optimus as #12 even though he's a different Prime, he's the Twelfth toy released in the US with that name. I didn't count off licencened toy as characters like the Playskool toys or the Animorphs. They were given a separate section. What helped me the most was Kenner's uniform scale they set up for Beast Wars. (which is still used by Hasbro today) Doug (Dlin) and I expanded out the size classes a little to incorporate all of the toys and came up with what we called the Beast Wars scale. Which goes something like this... Micro (mostly Micromasters and Mini-cons) Mini (Mini-vehicles and cassettes with most of the Spychangers) Basic/Scout (small toys like combiner limbs and the omni/terrorcons) Deluxe (the midway toy of all the lines from the G1 cars to the deluxe beasts and vehicles today) Mega/Voager (slightly larger toys or bulky short bots) Ultra (Combined robots and leaders from the older series) Super/Leader (the big bots and powered uped OP's) Supreme (as big as they make'em today or old Supers with lots of extras) Ultimate (the biggest, and only bot in this spot Fort Max) I also count physical Tech Spec stats with this scale.